CN118451580A - Secondary battery - Google Patents
Secondary battery Download PDFInfo
- Publication number
- CN118451580A CN118451580A CN202280086003.4A CN202280086003A CN118451580A CN 118451580 A CN118451580 A CN 118451580A CN 202280086003 A CN202280086003 A CN 202280086003A CN 118451580 A CN118451580 A CN 118451580A
- Authority
- CN
- China
- Prior art keywords
- electrolyte
- secondary battery
- positive electrode
- negative electrode
- lithium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003792 electrolyte Substances 0.000 claims abstract description 164
- -1 imide anion Chemical class 0.000 claims abstract description 111
- 150000003839 salts Chemical class 0.000 claims abstract description 85
- 150000001450 anions Chemical class 0.000 claims abstract description 31
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 29
- 229910052744 lithium Inorganic materials 0.000 claims description 29
- 229910001416 lithium ion Inorganic materials 0.000 claims description 28
- 150000001768 cations Chemical class 0.000 claims description 27
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims description 26
- 150000005676 cyclic carbonates Chemical class 0.000 claims description 19
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 claims description 16
- 125000000475 sulfinyl group Chemical group [*:2]S([*:1])=O 0.000 claims description 16
- 125000000472 sulfonyl group Chemical group *S(*)(=O)=O 0.000 claims description 16
- 125000001153 fluoro group Chemical group F* 0.000 claims description 14
- 125000003709 fluoroalkyl group Chemical group 0.000 claims description 14
- 125000002947 alkylene group Chemical group 0.000 claims description 10
- 150000008064 anhydrides Chemical class 0.000 claims description 10
- 229910021645 metal ion Inorganic materials 0.000 claims description 10
- 125000000843 phenylene group Chemical group C1(=C(C=CC=C1)*)* 0.000 claims description 8
- BTBUEUYNUDRHOZ-UHFFFAOYSA-N Borate Chemical compound [O-]B([O-])[O-] BTBUEUYNUDRHOZ-UHFFFAOYSA-N 0.000 claims description 7
- 239000012948 isocyanate Substances 0.000 claims description 6
- VDVLPSWVDYJFRW-UHFFFAOYSA-N lithium;bis(fluorosulfonyl)azanide Chemical compound [Li+].FS(=O)(=O)[N-]S(F)(=O)=O VDVLPSWVDYJFRW-UHFFFAOYSA-N 0.000 claims description 6
- 229910001496 lithium tetrafluoroborate Inorganic materials 0.000 claims description 5
- IGILRSKEFZLPKG-UHFFFAOYSA-M lithium;difluorophosphinate Chemical compound [Li+].[O-]P(F)(F)=O IGILRSKEFZLPKG-UHFFFAOYSA-M 0.000 claims description 5
- BDHFUVZGWQCTTF-UHFFFAOYSA-M sulfonate Chemical compound [O-]S(=O)=O BDHFUVZGWQCTTF-UHFFFAOYSA-M 0.000 claims description 4
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 2
- 239000008151 electrolyte solution Substances 0.000 abstract description 28
- 239000010410 layer Substances 0.000 description 63
- 238000012423 maintenance Methods 0.000 description 45
- 239000002904 solvent Substances 0.000 description 31
- 150000001875 compounds Chemical class 0.000 description 29
- 238000000034 method Methods 0.000 description 28
- 238000003860 storage Methods 0.000 description 27
- 239000000126 substance Substances 0.000 description 23
- 230000000694 effects Effects 0.000 description 22
- 239000000463 material Substances 0.000 description 21
- 239000007774 positive electrode material Substances 0.000 description 20
- 239000000203 mixture Substances 0.000 description 19
- 229920006280 packaging film Polymers 0.000 description 19
- 239000012785 packaging film Substances 0.000 description 19
- 229920000642 polymer Polymers 0.000 description 18
- 238000007789 sealing Methods 0.000 description 16
- 239000000654 additive Substances 0.000 description 15
- 230000000052 comparative effect Effects 0.000 description 15
- 239000007769 metal material Substances 0.000 description 14
- 238000005516 engineering process Methods 0.000 description 13
- 238000004519 manufacturing process Methods 0.000 description 13
- 229910052751 metal Inorganic materials 0.000 description 13
- 239000002184 metal Substances 0.000 description 13
- 239000004020 conductor Substances 0.000 description 12
- 238000003466 welding Methods 0.000 description 11
- 229910052782 aluminium Inorganic materials 0.000 description 10
- 238000000576 coating method Methods 0.000 description 10
- 239000007773 negative electrode material Substances 0.000 description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 9
- 239000006183 anode active material Substances 0.000 description 9
- 238000003411 electrode reaction Methods 0.000 description 9
- 230000004048 modification Effects 0.000 description 9
- 238000012986 modification Methods 0.000 description 9
- 230000006641 stabilisation Effects 0.000 description 9
- 238000011105 stabilization Methods 0.000 description 9
- 230000000996 additive effect Effects 0.000 description 8
- 239000011248 coating agent Substances 0.000 description 8
- 239000006258 conductive agent Substances 0.000 description 8
- 238000001514 detection method Methods 0.000 description 8
- 239000002002 slurry Substances 0.000 description 7
- YEJRWHAVMIAJKC-UHFFFAOYSA-N 4-Butyrolactone Chemical compound O=C1CCCO1 YEJRWHAVMIAJKC-UHFFFAOYSA-N 0.000 description 6
- 238000004364 calculation method Methods 0.000 description 6
- 238000007600 charging Methods 0.000 description 6
- 125000004122 cyclic group Chemical group 0.000 description 6
- 239000011883 electrode binding agent Substances 0.000 description 6
- 230000006870 function Effects 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- 239000004743 Polypropylene Substances 0.000 description 5
- 239000003575 carbonaceous material Substances 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 238000009831 deintercalation Methods 0.000 description 5
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 5
- 238000009830 intercalation Methods 0.000 description 5
- 239000003960 organic solvent Substances 0.000 description 5
- 230000002093 peripheral effect Effects 0.000 description 5
- 229920001155 polypropylene Polymers 0.000 description 5
- 239000002243 precursor Substances 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- FSSPGSAQUIYDCN-UHFFFAOYSA-N 1,3-Propane sultone Chemical compound O=S1(=O)CCCO1 FSSPGSAQUIYDCN-UHFFFAOYSA-N 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 4
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 4
- 229910013872 LiPF Inorganic materials 0.000 description 4
- 101150058243 Lipf gene Proteins 0.000 description 4
- 239000002033 PVDF binder Substances 0.000 description 4
- 230000009471 action Effects 0.000 description 4
- 239000000470 constituent Substances 0.000 description 4
- 238000007599 discharging Methods 0.000 description 4
- 238000004993 emission spectroscopy Methods 0.000 description 4
- 239000011888 foil Substances 0.000 description 4
- 125000000524 functional group Chemical group 0.000 description 4
- 238000009616 inductively coupled plasma Methods 0.000 description 4
- 229910003002 lithium salt Inorganic materials 0.000 description 4
- 159000000002 lithium salts Chemical class 0.000 description 4
- 125000004433 nitrogen atom Chemical group N* 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 4
- 239000011241 protective layer Substances 0.000 description 4
- 238000004804 winding Methods 0.000 description 4
- FALRKNHUBBKYCC-UHFFFAOYSA-N 2-(chloromethyl)pyridine-3-carbonitrile Chemical compound ClCC1=NC=CC=C1C#N FALRKNHUBBKYCC-UHFFFAOYSA-N 0.000 description 3
- BJWMSGRKJIOCNR-UHFFFAOYSA-N 4-ethenyl-1,3-dioxolan-2-one Chemical compound C=CC1COC(=O)O1 BJWMSGRKJIOCNR-UHFFFAOYSA-N 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- 239000005057 Hexamethylene diisocyanate Substances 0.000 description 3
- 229910013870 LiPF 6 Inorganic materials 0.000 description 3
- 229910052783 alkali metal Inorganic materials 0.000 description 3
- 150000001340 alkali metals Chemical class 0.000 description 3
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 3
- 150000001342 alkaline earth metals Chemical class 0.000 description 3
- JFDZBHWFFUWGJE-UHFFFAOYSA-N benzonitrile Chemical compound N#CC1=CC=CC=C1 JFDZBHWFFUWGJE-UHFFFAOYSA-N 0.000 description 3
- 125000004432 carbon atom Chemical group C* 0.000 description 3
- 239000011889 copper foil Substances 0.000 description 3
- VEWLDLAARDMXSB-UHFFFAOYSA-N ethenyl sulfate;hydron Chemical compound OS(=O)(=O)OC=C VEWLDLAARDMXSB-UHFFFAOYSA-N 0.000 description 3
- 229910052731 fluorine Inorganic materials 0.000 description 3
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 description 3
- 230000002687 intercalation Effects 0.000 description 3
- 238000005304 joining Methods 0.000 description 3
- 150000002596 lactones Chemical class 0.000 description 3
- 239000005001 laminate film Substances 0.000 description 3
- 229920000098 polyolefin Polymers 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 229920005989 resin Polymers 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 229940014800 succinic anhydride Drugs 0.000 description 3
- IAHFWCOBPZCAEA-UHFFFAOYSA-N succinonitrile Chemical compound N#CCCC#N IAHFWCOBPZCAEA-UHFFFAOYSA-N 0.000 description 3
- AVPYLKIIPLFMHQ-UHFFFAOYSA-N 1,2,6-oxadithiane 2,2,6,6-tetraoxide Chemical compound O=S1(=O)CCCS(=O)(=O)O1 AVPYLKIIPLFMHQ-UHFFFAOYSA-N 0.000 description 2
- VAYTZRYEBVHVLE-UHFFFAOYSA-N 1,3-dioxol-2-one Chemical compound O=C1OC=CO1 VAYTZRYEBVHVLE-UHFFFAOYSA-N 0.000 description 2
- QQJFVTIFADPLJE-UHFFFAOYSA-N C(O)(=O)F.C=C Chemical compound C(O)(=O)F.C=C QQJFVTIFADPLJE-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- XTHFKEDIFFGKHM-UHFFFAOYSA-N Dimethoxyethane Chemical compound COCCOC XTHFKEDIFFGKHM-UHFFFAOYSA-N 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- 229910013063 LiBF 4 Inorganic materials 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 229910001413 alkali metal ion Inorganic materials 0.000 description 2
- 229910001420 alkaline earth metal ion Inorganic materials 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 239000011884 anode binding agent Substances 0.000 description 2
- 239000003125 aqueous solvent Substances 0.000 description 2
- 229910021383 artificial graphite Inorganic materials 0.000 description 2
- 229910052790 beryllium Inorganic materials 0.000 description 2
- ATBAMAFKBVZNFJ-UHFFFAOYSA-N beryllium atom Chemical compound [Be] ATBAMAFKBVZNFJ-UHFFFAOYSA-N 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- SVTMLGIQJHGGFK-UHFFFAOYSA-N carbonic acid;propa-1,2-diene Chemical compound C=C=C.OC(O)=O SVTMLGIQJHGGFK-UHFFFAOYSA-N 0.000 description 2
- HRSNTDPZHQCOGI-UHFFFAOYSA-N carbonyl difluoride ethene Chemical compound C=C.C(=O)(F)F HRSNTDPZHQCOGI-UHFFFAOYSA-N 0.000 description 2
- 150000001733 carboxylic acid esters Chemical class 0.000 description 2
- 150000005678 chain carbonates Chemical class 0.000 description 2
- 125000004093 cyano group Chemical group *C#N 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- FKRCODPIKNYEAC-UHFFFAOYSA-N ethyl propionate Chemical compound CCOC(=O)CC FKRCODPIKNYEAC-UHFFFAOYSA-N 0.000 description 2
- 239000011737 fluorine Substances 0.000 description 2
- GAEKPEKOJKCEMS-UHFFFAOYSA-N gamma-valerolactone Chemical compound CC1CCC(=O)O1 GAEKPEKOJKCEMS-UHFFFAOYSA-N 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 229910021469 graphitizable carbon Inorganic materials 0.000 description 2
- 229910010272 inorganic material Inorganic materials 0.000 description 2
- 239000011147 inorganic material Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 125000005647 linker group Chemical group 0.000 description 2
- 239000011244 liquid electrolyte Substances 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N phosphoric acid Substances OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 2
- 229920003051 synthetic elastomer Polymers 0.000 description 2
- 239000005061 synthetic rubber Substances 0.000 description 2
- 229910052723 transition metal Inorganic materials 0.000 description 2
- OQHXCCQBSGTCGM-UHFFFAOYSA-N 1,2,5-oxadithiolane 2,2,5,5-tetraoxide Chemical compound O=S1(=O)CCS(=O)(=O)O1 OQHXCCQBSGTCGM-UHFFFAOYSA-N 0.000 description 1
- QGVDSWMSHDZOMW-UHFFFAOYSA-N 1,3,2-dioxathiolane Chemical compound C1COSO1 QGVDSWMSHDZOMW-UHFFFAOYSA-N 0.000 description 1
- WNXJIVFYUVYPPR-UHFFFAOYSA-N 1,3-dioxolane Chemical compound C1COCO1 WNXJIVFYUVYPPR-UHFFFAOYSA-N 0.000 description 1
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- HNAGHMKIPMKKBB-UHFFFAOYSA-N 1-benzylpyrrolidine-3-carboxamide Chemical compound C1C(C(=O)N)CCN1CC1=CC=CC=C1 HNAGHMKIPMKKBB-UHFFFAOYSA-N 0.000 description 1
- UHOPWFKONJYLCF-UHFFFAOYSA-N 2-(2-sulfanylethyl)isoindole-1,3-dione Chemical compound C1=CC=C2C(=O)N(CCS)C(=O)C2=C1 UHOPWFKONJYLCF-UHFFFAOYSA-N 0.000 description 1
- HBZYYOYCJQHAEL-UHFFFAOYSA-N 2-[3-(dicyanomethylidene)inden-1-ylidene]propanedinitrile Chemical compound C1=CC=C2C(=C(C#N)C#N)CC(=C(C#N)C#N)C2=C1 HBZYYOYCJQHAEL-UHFFFAOYSA-N 0.000 description 1
- JVKXKIBYHWRLOJ-UHFFFAOYSA-N 2-hydroxyethyl methanesulfonate Chemical compound CS(=O)(=O)OCCO JVKXKIBYHWRLOJ-UHFFFAOYSA-N 0.000 description 1
- AWVNJBFNHGQUQU-UHFFFAOYSA-N 3-butoxypropanenitrile Chemical compound CCCCOCCC#N AWVNJBFNHGQUQU-UHFFFAOYSA-N 0.000 description 1
- VWEYDBUEGDKEHC-UHFFFAOYSA-N 3-methyloxathiolane 2,2-dioxide Chemical compound CC1CCOS1(=O)=O VWEYDBUEGDKEHC-UHFFFAOYSA-N 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 1
- 229920002943 EPDM rubber Polymers 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- VZCYOOQTPOCHFL-OWOJBTEDSA-N Fumaric acid Natural products OC(=O)\C=C\C(O)=O VZCYOOQTPOCHFL-OWOJBTEDSA-N 0.000 description 1
- JGFBQFKZKSSODQ-UHFFFAOYSA-N Isothiocyanatocyclopropane Chemical compound S=C=NC1CC1 JGFBQFKZKSSODQ-UHFFFAOYSA-N 0.000 description 1
- 229910004190 Li1.15(Mn0.65Ni0.22Co0.13)O2 Inorganic materials 0.000 description 1
- 229910008744 Li1.2Mn0.52Co0.175Ni0.1O2 Inorganic materials 0.000 description 1
- 229910013075 LiBF Inorganic materials 0.000 description 1
- 229910012278 LiCo0.98Al0.01Mg0.01O2 Inorganic materials 0.000 description 1
- 229910032387 LiCoO2 Inorganic materials 0.000 description 1
- 229910011857 LiFe0.3Mn0.7PO4 Inorganic materials 0.000 description 1
- 229910011990 LiFe0.5Mn0.5PO4 Inorganic materials 0.000 description 1
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 1
- 229910000668 LiMnPO4 Inorganic materials 0.000 description 1
- 229910013716 LiNi Inorganic materials 0.000 description 1
- 229910013825 LiNi0.33Co0.33Mn0.33O2 Inorganic materials 0.000 description 1
- 229910002991 LiNi0.5Co0.2Mn0.3O2 Inorganic materials 0.000 description 1
- 229910002995 LiNi0.8Co0.15Al0.05O2 Inorganic materials 0.000 description 1
- 229910003005 LiNiO2 Inorganic materials 0.000 description 1
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 1
- RJUFJBKOKNCXHH-UHFFFAOYSA-N Methyl propionate Chemical compound CCC(=O)OC RJUFJBKOKNCXHH-UHFFFAOYSA-N 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 239000004642 Polyimide Substances 0.000 description 1
- NPYPAHLBTDXSSS-UHFFFAOYSA-N Potassium ion Chemical compound [K+] NPYPAHLBTDXSSS-UHFFFAOYSA-N 0.000 description 1
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 1
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 1
- 229910008484 TiSi Inorganic materials 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- KXKVLQRXCPHEJC-UHFFFAOYSA-N acetic acid trimethyl ester Natural products COC(C)=O KXKVLQRXCPHEJC-UHFFFAOYSA-N 0.000 description 1
- 239000006230 acetylene black Substances 0.000 description 1
- BTGRAWJCKBQKAO-UHFFFAOYSA-N adiponitrile Chemical compound N#CCCCCC#N BTGRAWJCKBQKAO-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910001423 beryllium ion Inorganic materials 0.000 description 1
- PWOSZCQLSAMRQW-UHFFFAOYSA-N beryllium(2+) Chemical compound [Be+2] PWOSZCQLSAMRQW-UHFFFAOYSA-N 0.000 description 1
- 229910001593 boehmite Inorganic materials 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- OBNCKNCVKJNDBV-UHFFFAOYSA-N butanoic acid ethyl ester Natural products CCCC(=O)OCC OBNCKNCVKJNDBV-UHFFFAOYSA-N 0.000 description 1
- 229920005549 butyl rubber Polymers 0.000 description 1
- PWLNAUNEAKQYLH-UHFFFAOYSA-N butyric acid octyl ester Natural products CCCCCCCCOC(=O)CCC PWLNAUNEAKQYLH-UHFFFAOYSA-N 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000011203 carbon fibre reinforced carbon Substances 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 239000003013 cathode binding agent Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 238000010280 constant potential charging Methods 0.000 description 1
- 238000010277 constant-current charging Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- SVPZJHKVRMRREG-UHFFFAOYSA-N cyclopentanecarbonitrile Chemical compound N#CC1CCCC1 SVPZJHKVRMRREG-UHFFFAOYSA-N 0.000 description 1
- DFJYZCUIKPGCSG-UHFFFAOYSA-N decanedinitrile Chemical compound N#CCCCCCCCCC#N DFJYZCUIKPGCSG-UHFFFAOYSA-N 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- SXWUDUINABFBMK-UHFFFAOYSA-L dilithium;fluoro-dioxido-oxo-$l^{5}-phosphane Chemical compound [Li+].[Li+].[O-]P([O-])(F)=O SXWUDUINABFBMK-UHFFFAOYSA-L 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000011808 electrode reactant Substances 0.000 description 1
- 150000002148 esters Chemical group 0.000 description 1
- MVKYQTGCKJXECD-UHFFFAOYSA-N ethane-1,2-diol;prop-1-ene Chemical group CC=C.CC=C.OCCO MVKYQTGCKJXECD-UHFFFAOYSA-N 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- HHEIMYAXCOIQCJ-UHFFFAOYSA-N ethyl 2,2-dimethylpropanoate Chemical compound CCOC(=O)C(C)(C)C HHEIMYAXCOIQCJ-UHFFFAOYSA-N 0.000 description 1
- JBTWLSYIZRCDFO-UHFFFAOYSA-N ethyl methyl carbonate Chemical compound CCOC(=O)OC JBTWLSYIZRCDFO-UHFFFAOYSA-N 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000001530 fumaric acid Substances 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- VANNPISTIUFMLH-UHFFFAOYSA-N glutaric anhydride Chemical compound O=C1CCCC(=O)O1 VANNPISTIUFMLH-UHFFFAOYSA-N 0.000 description 1
- ZTOMUSMDRMJOTH-UHFFFAOYSA-N glutaronitrile Chemical compound N#CCCCC#N ZTOMUSMDRMJOTH-UHFFFAOYSA-N 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000012943 hotmelt Substances 0.000 description 1
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 229910003473 lithium bis(trifluoromethanesulfonyl)imide Inorganic materials 0.000 description 1
- QSZMZKBZAYQGRS-UHFFFAOYSA-N lithium;bis(trifluoromethylsulfonyl)azanide Chemical compound [Li+].FC(F)(F)S(=O)(=O)[N-]S(=O)(=O)C(F)(F)F QSZMZKBZAYQGRS-UHFFFAOYSA-N 0.000 description 1
- QVXQYMZVJNYDNG-UHFFFAOYSA-N lithium;bis(trifluoromethylsulfonyl)methylsulfonyl-trifluoromethane Chemical compound [Li+].FC(F)(F)S(=O)(=O)[C-](S(=O)(=O)C(F)(F)F)S(=O)(=O)C(F)(F)F QVXQYMZVJNYDNG-UHFFFAOYSA-N 0.000 description 1
- MCVFFRWZNYZUIJ-UHFFFAOYSA-M lithium;trifluoromethanesulfonate Chemical compound [Li+].[O-]S(=O)(=O)C(F)(F)F MCVFFRWZNYZUIJ-UHFFFAOYSA-M 0.000 description 1
- 229910001425 magnesium ion Inorganic materials 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229940017219 methyl propionate Drugs 0.000 description 1
- 125000001570 methylene group Chemical group [H]C([H])([*:1])[*:2] 0.000 description 1
- UUIQMZJEGPQKFD-UHFFFAOYSA-N n-butyric acid methyl ester Natural products CCCC(=O)OC UUIQMZJEGPQKFD-UHFFFAOYSA-N 0.000 description 1
- 229910021382 natural graphite Inorganic materials 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 239000011255 nonaqueous electrolyte Substances 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 229920006284 nylon film Polymers 0.000 description 1
- YSIMAPNUZAVQER-UHFFFAOYSA-N octanenitrile Chemical compound CCCCCCCC#N YSIMAPNUZAVQER-UHFFFAOYSA-N 0.000 description 1
- 125000001979 organolithium group Chemical group 0.000 description 1
- 230000001151 other effect Effects 0.000 description 1
- MHYFEEDKONKGEB-UHFFFAOYSA-N oxathiane 2,2-dioxide Chemical compound O=S1(=O)CCCCO1 MHYFEEDKONKGEB-UHFFFAOYSA-N 0.000 description 1
- 125000005004 perfluoroethyl group Chemical group FC(F)(F)C(F)(F)* 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- XQZYPMVTSDWCCE-UHFFFAOYSA-N phthalonitrile Chemical compound N#CC1=CC=CC=C1C#N XQZYPMVTSDWCCE-UHFFFAOYSA-N 0.000 description 1
- 229920006391 phthalonitrile polymer Polymers 0.000 description 1
- 229920001721 polyimide Polymers 0.000 description 1
- 229910001414 potassium ion Inorganic materials 0.000 description 1
- 230000003389 potentiating effect Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000004321 preservation Methods 0.000 description 1
- OWAHJGWVERXJMI-UHFFFAOYSA-N prop-2-ynyl methanesulfonate Chemical compound CS(=O)(=O)OCC#C OWAHJGWVERXJMI-UHFFFAOYSA-N 0.000 description 1
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 1
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 1
- 239000005060 rubber Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 150000003871 sulfonates Chemical class 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical group FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 238000007751 thermal spraying Methods 0.000 description 1
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 1
- 125000002023 trifluoromethyl group Chemical group FC(F)(F)* 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0567—Liquid materials characterised by the additives
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0566—Liquid materials
- H01M10/0568—Liquid materials characterised by the solutes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Secondary Cells (AREA)
Abstract
The secondary battery includes a positive electrode, a negative electrode, an electrolyte solution containing an electrolyte salt, a plurality of positive electrode terminals electrically connected to the positive electrode, and a plurality of negative electrode terminals electrically connected to the negative electrode. The electrolyte salt contains an imide anion containing at least one of anions represented by each of formula (1), formula (2), formula (3), and formula (4).
Description
Technical Field
The present technology relates to a secondary battery.
Background
A variety of electronic devices such as mobile phones are becoming popular, accordingly, secondary batteries have been developed as small-sized, lightweight power sources that can obtain high energy density. The secondary battery includes a positive electrode, a negative electrode, and an electrolyte, and various studies have been made on the structure of the secondary battery.
Specifically, the electrolyte contains an imide compound represented by R F 1-S(＝O)2-NH-S(＝O)2-NH-S(＝O)2-RF 2 (for example, refer to patent document 1). The electrolyte salt of the electrolyte solution contains an imide anion represented by F-S (=o) 2-N--C(＝O)-N--S(＝O)2 -F or F-S(＝O)2-N--S(＝O)2-C6H4-S(＝O)2-N--S(＝O)2-F (for example, refer to non-patent documents 1 and 2).
Prior art literature
Patent literature
Patent document 1: chinese patent No. 102786443.
Non-patent literature
Non-patent document 1: faiz Ahmed et al ,"Novel divalent organo-lithium salts with high electrochemical and thermal stability for aqueous rechargeable Li-Ion batteries",Electrochimica Acta,298,2019, 709-716
Non-patent document 2: faiz Ahmed et al ,"Highly conductive divalent fluorosulfonyl imide based electrolytes improving Li-ion battery performance:Additive potentiating",Journal of Power Sources,455,2020, 227980.
Disclosure of Invention
Although various studies have been made on the structure of the secondary battery, the battery characteristics of the secondary battery are not yet sufficient, and thus there is room for improvement.
A secondary battery that can obtain excellent battery characteristics is desired.
The secondary battery according to one embodiment of the present technology includes a positive electrode, a negative electrode, an electrolyte solution containing an electrolyte salt, a plurality of positive electrode terminals electrically connected to the positive electrode, and a plurality of negative electrode terminals electrically connected to the negative electrode. The electrolyte salt contains an imide anion containing at least one of anions represented by each of formula (1), formula (2), formula (3), and formula (4).
[ Chemical formula 1]
( Each of R1 and R2 is any one of a fluoro group and a fluoroalkyl group. Each of W1, W2, and W3 is any one of carbonyl (> c=o), sulfinyl (> s=o), and sulfonyl (> S (=o) 2). )
[ Chemical formula 2]
( Each of R3 and R4 is any one of a fluoro group and a fluoroalkyl group. Each of X1, X2, X3, and X4 is any one of carbonyl, sulfinyl, and sulfonyl. )
[ Chemical formula 3]
( R5 is a fluoroalkylene group. Each of Y1, Y2, and Y3 is any one of carbonyl, sulfinyl, and sulfonyl. )
[ Chemical formula 4]
( Each of R6 and R7 is any one of a fluoro group and a fluoroalkyl group. R8 is any one of alkylene, phenylene, fluoroalkylene and fluoroalkylene. Each of Z1, Z2, Z3, and Z4 is any one of carbonyl, sulfinyl, and sulfonyl. )
According to the secondary battery of one embodiment of the present technology, the plurality of positive electrode terminals are electrically connected to the positive electrode, the plurality of negative electrode terminals are electrically connected to the negative electrode, and the electrolyte salt of the electrolytic solution contains at least one of anions represented by each of formulas (1), (2), (3) and (4) as an imide anion, so that excellent battery characteristics can be obtained.
The effects of the present technology are not necessarily limited to those described herein, and may be any of a series of effects related to the present technology described below.
Drawings
Fig. 1 is a perspective view showing the structure of a secondary battery in one embodiment of the present technology.
Fig. 2 is a sectional view showing the structure of the battery element shown in fig. 1.
Fig. 3 is a plan view showing the structure of the positive electrode shown in fig. 2.
Fig. 4 is a plan view showing the structure of the negative electrode shown in fig. 2.
Fig. 5 is a perspective view for explaining a method of manufacturing the secondary battery.
Fig. 6 is a perspective view showing the structure of the secondary battery of the comparative example.
Fig. 7 is a block diagram showing the structure of an application example of the secondary battery.
Detailed Description
An embodiment of the present technology will be described in detail below with reference to the accompanying drawings. The procedure described is as follows.
1. Secondary battery
1-1 Structure
1-2. Action
1-3 Method of manufacture
1-4 Actions and effects
2. Modification examples
3. Use of secondary battery
< 1 Secondary Battery >)
First, a secondary battery according to an embodiment of the present technology will be described.
The secondary battery described here is a secondary battery having a battery capacity obtained by intercalation and deintercalation of an electrode reactant, and includes a positive electrode, a negative electrode, and an electrolyte.
In this secondary battery, the charge capacity of the negative electrode is larger than the discharge capacity of the positive electrode. That is, the electrochemical capacity per unit area of the negative electrode is set to be larger than the electrochemical capacity per unit area of the positive electrode. This is because precipitation of the electrode reaction material on the surface of the negative electrode during charging is prevented.
The type of the electrode reaction substance is not particularly limited, and specifically, the electrode reaction substance is a light metal such as an alkali metal or an alkaline earth metal. Specific examples of the alkali metal are lithium, sodium, potassium, and the like, and specific examples of the alkaline earth metal are beryllium, magnesium, calcium, and the like. However, the type of the electrode reaction material may be other light metals such as aluminum.
Hereinafter, the case where the electrode reaction material is lithium is exemplified. A secondary battery that utilizes intercalation and deintercalation of lithium to obtain battery capacity is a so-called lithium ion secondary battery. In this lithium ion secondary battery, lithium is intercalated and deintercalated in an ionic state.
< 1-1. Structure >
Fig. 1 shows a three-dimensional structure of a secondary battery, and fig. 2 shows a cross-sectional structure of the battery element 20 shown in fig. 1. Fig. 3 shows a top view of the positive electrode 21 shown in fig. 2, and fig. 4 shows a top view of the negative electrode 22 shown in fig. 2. However, in fig. 1, the outer packaging film 10 and the battery element 20 are shown in a state of being separated from each other, and in fig. 2, only a part of the battery element 20 is shown.
As shown in fig. 1 and 2, the secondary battery includes: the external packaging film 10, the battery element 20, the plurality of positive electrode terminals 31, the plurality of negative electrode terminals 32, the positive electrode lead 41, the negative electrode lead 42, and the sealing films 51, 52.
As described above, the secondary battery described here has a so-called multi-collector structure because it includes a plurality of positive electrode terminals 31 and a plurality of negative electrode terminals 32. Further, as described above, the secondary battery uses the flexible or pliable exterior film 10 as an exterior material, and is a so-called laminate film type secondary battery.
[ Outer packaging film ]
As shown in fig. 1, the exterior film 10 is an exterior material that houses the battery element 20, and has a bag-like structure that is sealed in a state in which the battery element 20 is housed inside. Thus, the outer coating film 10 accommodates the positive electrode 21, the negative electrode 22, and the electrolyte solution, which will be described later.
Here, the outer packaging film 10 is a film-like member folded in the folding direction F. The exterior film 10 is provided with a recess 10U (so-called deep drawn portion) for accommodating the battery element 20.
Specifically, the exterior film 10 is a three-layer laminated film in which a welded layer, a metal layer, and a surface protective layer are laminated in this order from the inside, and outer peripheral edges of the welded layers facing each other are welded to each other in a state where the exterior film 10 is folded. The weld layer contains a polymer compound such as polypropylene. The metal layer contains a metal material such as aluminum. The surface protective layer contains a polymer compound such as nylon.
However, the structure (number of layers) of the outer packaging film 10 is not particularly limited, and may be one or two or four or more layers.
[ Battery element ]
As shown in fig. 1 to 4, the battery element 20 is a power generating element including a positive electrode 21, a negative electrode 22, a separator 23, and an electrolyte (not shown), and is housed inside the exterior film 10.
Here, the battery element 20 is a so-called laminated electrode body. That is, in the battery element 20, the positive electrode 21 and the negative electrode 22 are stacked on each other via the separator 23. More specifically, the battery element 20 includes a plurality of positive electrodes 21, a plurality of negative electrodes 22, and a plurality of separators 23, and therefore the positive electrodes 21 and the negative electrodes 22 are alternately laminated via the separators 23. The number of each of the positive electrode 21, the negative electrode 22, and the separator 23 is not particularly limited, and thus can be arbitrarily set.
(Cathode)
As shown in fig. 2 and 3, the positive electrode 21 includes a positive electrode current collector 21A and a positive electrode active material layer 21B. In fig. 3, the positive electrode active material layer 21B is hatched.
The positive electrode current collector 21A has a pair of surfaces on which the positive electrode active material layer 21B is provided. The positive electrode current collector 21A includes a conductive material such as a metal material, and a specific example of the metal material is aluminum or the like.
The positive electrode active material layer 21B contains any one or two or more positive electrode active materials capable of intercalating and deintercalating lithium. However, the positive electrode active material layer 21B may contain any one or two or more of other materials such as a positive electrode binder and a positive electrode conductive agent.
Here, the positive electrode active material layers 21B are provided on both sides of the positive electrode current collector 21A. However, the positive electrode active material layer 21B may be provided on only one surface of the positive electrode current collector 21A on the side where the positive electrode 21 and the negative electrode 22 face each other. The method for forming the positive electrode active material layer 21B is not particularly limited, and specifically, any one or two or more of coating methods and the like are used.
The type of the positive electrode active material is not particularly limited, and specifically, a lithium-containing compound or the like. The lithium-containing compound is a compound containing lithium and one or two or more transition metal elements as constituent elements, and may contain one or two or more other elements as constituent elements. The kind of the other element is not particularly limited as long as it is an element other than lithium and the transition metal element, and specifically, it is an element belonging to groups 2 to 15 of the long period periodic table. The type of the lithium-containing compound is not particularly limited, and specifically, the lithium-containing compound is an oxide, a phosphoric acid compound, a silicic acid compound, a boric acid compound, or the like.
Specific examples of the oxide are LiNiO2、LiCoO2、LiCo0.98Al0.01Mg0.01O2、LiNi0.5Co0.2Mn0.3O2、LiNi0.8Co0.15Al0.05O2、LiNi0.33Co0.33Mn0.33O2、Li1.2Mn0.52Co0.175Ni0.1O2、Li1.15(Mn0.65Ni0.22Co0.13)O2, liMn 2O4, and the like. Specific examples of the phosphoric acid compound are LiFePO 4、LiMnPO4、LiFe0.5Mn0.5PO4, liFe 0.3Mn0.7PO4, and the like.
The positive electrode binder contains one or more of synthetic rubber, a polymer compound, and the like. Specific examples of the synthetic rubber are butyl rubber, fluorine rubber, ethylene propylene diene monomer rubber, and the like. Specific examples of the polymer compound include polyvinylidene fluoride, polyimide, and carboxymethyl cellulose.
The positive electrode conductive agent contains one or two or more of conductive materials such as carbon materials, and specific examples of the carbon materials include graphite, carbon black, acetylene black, ketjen black, and the like. However, the conductive material may be a metal material, a polymer compound, or the like.
Here, as shown in fig. 3, a part of the positive electrode collector 21A protrudes, and therefore, the positive electrode collector 21A includes a portion protruding further outward than the positive electrode active material layer 21B (hereinafter, referred to as "protruding portion of the positive electrode collector 21A"). Since the positive electrode active material layer 21B is not provided at the protruding portion of the positive electrode current collector 21A, the protruding portion of the positive electrode current collector 21A functions as the positive electrode terminal 31. The details of the positive electrode terminal 31 will be described below.
(Negative electrode)
As shown in fig. 2 and 3, the anode 22 includes an anode current collector 22A and an anode active material layer 22B. In fig. 3, the anode active material layer 22B is hatched.
The negative electrode current collector 22A has a pair of surfaces on which the negative electrode active material layer 22B is provided. The negative electrode current collector 22A includes a conductive material such as a metal material, and a specific example of the metal material is copper or the like.
The anode active material layer 22B contains any one or two or more of anode active materials capable of intercalating and deintercalating lithium. However, the anode active material layer 22B may contain any one or two or more of other materials such as an anode binder and an anode conductive agent.
Here, the anode active material layers 22B are provided on both sides of the anode current collector 22A. However, the anode active material layer 22B may be provided on only one surface of the anode current collector 22A on the side of the anode 22 facing the cathode 21. The method for forming the anode active material layer 22B is not particularly limited, and specifically, is any one or two or more of a coating method, a gas phase method, a liquid phase method, a thermal spraying method, a firing method (sintering method), and the like.
The type of the negative electrode active material is not particularly limited, and specifically, is one or both of a carbon material and a metal material. This is because a high energy density is obtained. Specific examples of the carbon material are easily graphitizable carbon, hardly graphitizable carbon, and graphite (natural graphite and artificial graphite), and the like. The metal-based material is a material containing, as constituent elements, one or more of a metal element and a half metal element capable of forming an alloy with lithium, and specific examples of the metal element and the half metal element are one or both of silicon and tin. The metal-based material may be a single body, an alloy, a compound, a mixture of two or more of them, or a material containing two or more of them. Specific examples of the metal-based material include TiSi 2 and SiO x (0 < x.ltoreq.2 or 0.2 < x < 1.4).
Details regarding each of the anode binder and the anode conductive agent are the same as those regarding each of the cathode binder and the cathode conductive agent.
Here, as shown in fig. 4, since a part of the negative electrode collector 22A protrudes, the negative electrode collector 22A includes a portion protruding further outward than the negative electrode active material layer 22B (hereinafter, referred to as "protruding portion of the negative electrode collector 22A").
The protruding direction of the protruding portion of the negative electrode current collector 22A is the same direction as the protruding direction of the protruding portion of the positive electrode current collector 21A. The position of the protruding portion of the negative electrode current collector 22A is a position that does not overlap with the protruding portion of the positive electrode current collector 21A when the positive electrode 21 and the negative electrode 22 are alternately stacked via the separator 23.
Since the negative electrode active material layer 22B is not provided at the protruding portion of the negative electrode current collector 22A, the protruding portion of the negative electrode current collector 22A functions as the negative electrode terminal 32. In addition, details of the negative electrode terminal 32 will be described below.
(Diaphragm)
As shown in fig. 2, the separator 23 is an insulating porous film interposed between the positive electrode 21 and the negative electrode 22, and allows lithium ions to pass through while preventing contact (short circuit) between the positive electrode 21 and the negative electrode 22. The separator 23 contains a polymer compound such as polyethylene.
(Electrolyte)
The electrolyte is a liquid electrolyte. The electrolyte is impregnated in each of the positive electrode 21, the negative electrode 22, and the separator 23, and contains an electrolyte salt. More specifically, the electrolyte solution contains an electrolyte salt and a solvent that disperses or dissolves the electrolyte salt.
[ Electrolyte salt ]
Electrolyte salts are compounds that ionize in a solvent, containing anions as well as cations. However, the electrolyte salt may be one kind or two or more kinds.
(Anions)
The anion contains an imide anion containing any one or two or more of anions represented by each of the formula (1), the formula (2), the formula (3), and the formula (4). That is, the electrolyte salt contains an imide anion as an anion.
Hereinafter, the anion represented by the formula (1) is referred to as a "first imide anion", the anion represented by the formula (2) is referred to as a "second imide anion", the anion represented by the formula (3) is referred to as a "third imide anion", and the anion represented by the formula (4) is referred to as a "fourth imide anion".
However, the first imide anion may be one kind or two or more kinds. In this way, the species may be one kind or two or more kinds, and the same applies to each of the second imide anion, the third imide anion, and the fourth imide anion.
[ Chemical formula 5]
( Each of R1 and R2 is any one of a fluoro group and a fluoroalkyl group. Each of W1, W2, and W3 is any one of carbonyl, sulfinyl, and sulfonyl. )
[ Chemical formula 6]
( Each of R3 and R4 is any one of a fluoro group and a fluoroalkyl group. Each of X1, X2, X3, and X4 is any one of carbonyl, sulfinyl, and sulfonyl. )
[ Chemical formula 7]
( R5 is a fluoroalkylene group. Each of Y1, Y2, and Y3 is any one of carbonyl, sulfinyl, and sulfonyl. )
[ Chemical formula 8]
( Each of R6 and R7 is any one of a fluoro group and a fluoroalkyl group. R8 is any one of alkylene, phenylene, fluoroalkylene and fluoroalkylene. Each of Z1, Z2, Z3, and Z4 is any one of carbonyl, sulfinyl, and sulfonyl. )
The reason for the anions comprising imide anions is as described below. First, this is because a high-quality coating film from an electrolyte salt is formed on the surface of each of the positive electrode 21 and the negative electrode 22 at the time of charge and discharge of the secondary battery using the electrolyte. Thereby, the reaction of the electrolyte (particularly, the solvent) with each of the positive electrode 21 and the negative electrode 22 is suppressed, and thus the decomposition of the electrolyte is suppressed. Second, with the above-described coating film, the movement speed of the cations is increased in the vicinity of the surface of each of the positive electrode 21 and the negative electrode 22. Third, the movement speed of cations in the liquid of the electrolyte is also increased.
As shown in formula (1), the first imide anion is a chain anion (divalent anion) containing two nitrogen atoms (N) and three functional groups (W1 to W3).
Each of R1 and R2 is not particularly limited as long as it is any one of a fluoro group (-F) and a fluoroalkyl group. That is, each of R1 and R2 may be the same group as each other or may be a group different from each other. Thus, each of R1 and R2 is not a hydrogen group (-H), an alkyl group, or the like.
Fluoroalkyl is a group in which one or more hydrogen groups (-H) in the alkyl group are substituted with a fluoro group. However, the fluoroalkyl group may be linear or branched having one or more side chains.
The number of carbon atoms of the fluoroalkyl group is not particularly limited, and specifically 1 to 10. This is because the solubility and ionization of the electrolyte salt containing the first imide anion are improved.
Specific examples of fluoroalkyl groups are perfluoromethyl groups (-CF 3), perfluoroethyl groups (-C 2F5), and the like.
Each of W1 to W3 is not particularly limited as long as it is any one of carbonyl group, sulfinyl group and sulfonyl group. That is, each of W1 to W3 may be the same group as each other or may be a group different from each other. Of course, only any two of W1 to W3 may be the same group as each other.
As shown in formula (2), the second imide anion is a chain anion (trivalent anion) containing three nitrogen atoms and four functional groups (X1 to X4).
The details about each of R3 and R4 are the same as those about each of R1 and R2.
Each of X1 to X4 is not particularly limited as long as it is any one of carbonyl group, sulfinyl group and sulfonyl group. That is, each of X1 to X4 may be the same group as each other or may be a group different from each other. Of course, only any two of X1 to X4 may be the same group as each other, or only any three of X1 to X4 may be the same group as each other.
As shown in formula (3), the third imide anion is a cyclic anion (divalent anion) containing two nitrogen atoms, three functional groups (Y1 to Y3), and one linking group (R5).
The fluoroalkylene group as R5 is a group in which one or two or more hydrogen groups in the alkylene group are substituted with a fluorine group. However, the fluoroalkylene group may be linear or branched having one or more side chains.
The number of carbon atoms of the fluoroalkylene group is not particularly limited, and specifically 1 to 10. This is because the solubility and ionization of the electrolyte salt containing the third imide anion are improved.
Specific examples of the fluoroalkylene group include a perfluoromethylene group (-CF 2 -) and a perfluoroethylene group (-C 2F4 -).
Each of Y1 to Y3 is not particularly limited as long as it is any one of carbonyl group, sulfinyl group and sulfonyl group. That is, each of Y1 to Y3 may be the same group as each other or may be a group different from each other. Of course, only any two of Y1 to Y3 may be the same groups as each other.
As shown in formula (4), the fourth imide anion is a chain anion (divalent anion) containing two nitrogen atoms (N), four functional groups (Z1 to Z4), and one linking group (R8).
The details about each of R6 and R7 are the same as those about each of R1 and R2.
R8 is not particularly limited as long as it is any one of alkylene, phenylene, fluoroalkylene and fluoroalkylene.
The alkylene group may be linear or branched having one or more side chains. The number of carbon atoms of the alkylene group is not particularly limited, and specifically, 1 to 10. This is because the solubility and ionization of the electrolyte salt containing the fourth imide anion are improved. Specific examples of alkylene groups are methylene (-CH 2 -), ethylene (-C 2H4 -), propylene (-C 3H6 -), and the like.
Details concerning the fluorinated alkylene group as R8 are the same as those concerning the fluorinated alkylene group as R5.
A fluorinated phenylene group is a group in which one or more hydrogen groups in the phenylene group are substituted with a fluorine group. Specific examples of the fluorinated phenylene group include monofluorinated phenylene group (-C 6H3 F-), and the like.
Each of Z1 to Z4 is not particularly limited as long as it is any one of carbonyl group, sulfinyl group and sulfonyl group. That is, each of Z1 to Z4 may be the same group as each other or may be a group different from each other. Of course, only any two of Z1 to Z4 may be the same groups as each other, or only any three of Z1 to Z4 may be the same groups as each other.
Specific examples of the first imide anion are anions represented by each of the formulas (1-1) to (1-30), and the like.
[ Chemical formula 9]
[ Chemical formula 10]
[ Chemical formula 11]
Specific examples of the second imide anion are anions represented by each of the formulas (2-1) to (2-22), and the like.
[ Chemical formula 12]
[ Chemical formula 13]
Specific examples of the third imide anion are anions represented by each of the formulas (3-1) to (3-15), and the like.
[ Chemical formula 14]
Specific examples of the fourth imide anion are anions represented by each of the formulas (4-1) to (4-65), and the like.
[ Chemical formula 15]
[ Chemical formula 16]
[ Chemical formula 17 ]
[ Chemical formula 18 ]
[ Chemical formula 19 ]
[ Chemical formula 20 ]
[ Chemical formula 21 ]
(Cation)
The kind of the cation is not particularly limited. Specifically, the cations include any one or two or more of light metal ions. That is, the electrolyte salt contains light metal ions as cations. This is because a high voltage is obtained.
The type of the light metal ion is not particularly limited, and specifically, alkali metal ions, alkaline earth metal ions, and the like. Specific examples of the alkali metal ion are sodium ion, potassium ion, and the like. Specific examples of the alkaline earth metal ion include beryllium ion, magnesium ion, and calcium ion. The light metal ion may be aluminum ion or the like.
Among them, the light metal ion preferably contains lithium ion. This is because a sufficiently high voltage is obtained.
(Content)
The content of the electrolyte salt in the electrolyte solution is not particularly limited, and thus can be arbitrarily set. Among them, the content of the electrolyte salt is preferably 0.2mol/kg to 2mol/kg. This is because high ion conductivity is obtained. The "content of electrolyte salt" as referred to herein refers to the content of electrolyte salt relative to the solvent.
In the case where the content of the electrolyte salt is to be determined, after the electrolyte is recovered by disassembling the secondary battery, the electrolyte is analyzed using an inductively coupled high-frequency plasma (Inductively Coupled Plasma (ICP)) emission spectrometry. Thus, the weight of the solvent and the weight of the electrolyte salt were determined, respectively, and thus the content of the electrolyte salt was calculated.
The content determination step described here is also similar to the case of determining the content of the components of the electrolyte other than the electrolyte salt described later. The "component of the electrolyte solution other than the electrolyte salt" means other electrolyte salts, additives, and the like.
[ Solvent ]
The solvent includes any one or two or more of nonaqueous solvents (organic solvents), and the electrolyte including the nonaqueous solvents is a so-called nonaqueous electrolyte. The nonaqueous solvent is an ester, an ether, or the like, and more specifically, a carbonate compound, a carboxylate compound, a lactone compound, or the like.
The carbonate compound is a cyclic carbonate, a chain carbonate, or the like. Specific examples of the cyclic carbonate are ethylene carbonate, propylene carbonate and the like. Specific examples of the chain carbonates are dimethyl carbonate, diethyl carbonate, and methylethyl carbonate.
The carboxylic acid ester compound is a chain carboxylic acid ester or the like. Specific examples of the chain carboxylic acid esters are methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, propyl propionate, ethyl trimethylacetate, methyl butyrate, ethyl butyrate, and the like.
The lactone compound is a lactone or the like. Specific examples of lactones are gamma-butyrolactone and gamma-valerolactone.
The ethers may be 1, 2-dimethoxyethane, tetrahydrofuran, 1, 3-dioxolane, 1, 4-dioxane, etc.
[ Other electrolyte salt ]
The electrolyte may further contain any one or two or more of other electrolyte salts. This is because the movement speed of the cations is more increased near the surface of each of the positive electrode 21 and the negative electrode 22, and the movement speed of the cations is also more increased in the liquid of the electrolyte. The content of the other electrolyte salt in the electrolyte solution is not particularly limited, and thus can be arbitrarily set.
The type of the other electrolyte salt is not particularly limited, and specifically, a light metal salt such as a lithium salt. However, the above electrolyte salts are excluded from the lithium salts described herein.
Specific examples of the lithium salt are lithium hexafluorophosphate (LiPF 6), lithium tetrafluoroborate (LiBF 4), lithium trifluoromethane sulfonate (LiCF 3SO3), lithium bis (fluorosulfonyl) imide (LiN (FSO 2)2), lithium bis (trifluoromethane sulfonyl) imide (LiN (CF 3SO2)2), lithium tris (trifluoromethane sulfonyl) methide (LiC (CF 3SO2)3), lithium bis (oxalato) borate (LiB (C 2O4)2), lithium difluorooxalato borate (LiBF 2(C2O4)), lithium difluorobis (oxalato) borate (LiPF 2(C2O4)2), lithium tetrafluorooxalato phosphate (LiPF 4(C2O4), lithium monofluorophosphate (Li 2PFO3), lithium difluorophosphate (LiPF 2O2), and the like.
Among them, the other electrolyte salt preferably contains any one or two or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis (fluorosulfonyl) imide, lithium bis (oxalato) borate, and lithium difluorophosphate. This is because the movement speed of lithium ions is sufficiently increased near the surface of each of the positive electrode 21 and the negative electrode 22, and the movement speed of lithium ions is also sufficiently increased in the liquid of the electrolyte.
[ Additive ]
In addition, the electrolyte may further contain any one or two or more additives. This is because, at the time of charge and discharge of the secondary battery using the electrolyte, a coating film from the additive is formed on the surface of each of the positive electrode 21 and the negative electrode 22, and thus the decomposition reaction of the electrolyte is suppressed. The content of the additive in the electrolyte is not particularly limited, and thus can be arbitrarily set.
The type of the additive is not particularly limited, and specifically, unsaturated cyclic carbonates, fluorinated cyclic carbonates, sulfonates, dicarboxylic anhydrides, disulfonic anhydrides, sulfates, nitrile compounds, isocyanate compounds, and the like.
Unsaturated cyclic carbonates are cyclic carbonates containing unsaturated carbon bonds (carbon-carbon double bonds). The number of unsaturated carbon bonds is not particularly limited, and may be one or two or more. Specific examples of the unsaturated cyclic carbonates are ethylene carbonate, vinyl ethylene carbonate, methylene ethylene carbonate and the like.
The fluorinated cyclic carbonate is a cyclic carbonate containing fluorine as a constituent element. That is, the fluorinated cyclic carbonate is a compound in which one or two or more hydrogen groups in the cyclic carbonate are substituted with a fluorine group. Specific examples of the fluorinated cyclic carbonate include ethylene monofluorocarbonate and ethylene difluorocarbonate.
The sulfonate is a cyclic monosulfonate, a cyclic disulfonate, a chain monosulfonate, a chain disulfonate, or the like. Specific examples of cyclic monosulfonates are 1, 3-propane sultone, 1-propylene-1, 3-sultone, 1, 4-butane sultone, 2, 4-butane sultone, propargyl methanesulfonate, and the like. Specific examples of the cyclic disulfonate are ethylene glycol methylsulfonate and the like.
Specific examples of dicarboxylic anhydrides are succinic anhydride, glutaric anhydride, maleic anhydride, and the like. Specific examples of disulfonic anhydride are ethane disulfonic anhydride, propane disulfonic anhydride, and the like. Specific examples of the sulfate esters are vinyl sulfate (1, 3, 2-dioxazothiophene 2,2-dioxide (1, 3,2-dioxathiolane, 2-dioxide)), and the like.
The nitrile compound is a compound containing one or more cyano groups (-CN). Specific examples of the nitrile compound are octanenitrile, benzonitrile, phthalonitrile, succinonitrile, glutaronitrile, adiponitrile, sebaconitrile, 1,3, 6-hexanetrinitrile, 3' -oxydipropionitrile, 3-butoxypropionitrile, ethylene glycol dipropylene nitrile ether, 1,2, 3-tetracyanopropane, fumaric acid nitrile, 7, 8-tetracyanoquinodimethane, cyanocyclopentane, 1,3, 5-cyclohexanedinitrile, 1, 3-bis (dicyanomethylene) indane and the like.
The isocyanate compound is a compound containing one or more isocyanate groups (-NCO). Specific examples of the isocyanate compound are hexamethylene diisocyanate and the like.
[ Positive electrode terminals and negative electrode terminals ]
As shown in fig. 3, the positive electrode terminal 31 is electrically connected to the positive electrode 21, more specifically, to the positive electrode current collector 21A. In addition, in the battery element 20, as described above, the positive electrodes 21 and the negative electrodes 22 are alternately laminated via the separator 23, and therefore the battery element 20 includes a plurality of positive electrodes 21. Thus, the secondary battery includes a plurality of positive electrode terminals 31. The number of positive electrode terminals 31 is not particularly limited as long as it is two or more, and thus can be arbitrarily set.
The positive electrode terminal 31 includes a conductive material such as a metal material, and the type of the conductive material is not particularly limited. Specifically, the positive electrode terminal 31 contains the same material as the material forming the positive electrode current collector 21A.
Here, since the protruding portion of the positive electrode collector 21A functions as the positive electrode terminal 31 as described above, the positive electrode terminal 31 is physically integrated with the positive electrode collector 21A. This is because the connection resistance between the positive electrode current collector 21A and the positive electrode terminal 31 decreases, and thus the resistance of the entire secondary battery decreases.
As described later, the plurality of positive electrode terminals 31 are bonded to each other by a bonding method such as welding, and therefore, as shown in fig. 1, one linear bonding portion 31Z is formed.
As shown in fig. 4, the negative electrode terminal 32 is electrically connected to the negative electrode 22, more specifically, to the negative electrode current collector 22A. In addition, in the battery element 20, as described above, the positive electrodes 21 and the negative electrodes 22 are alternately laminated via the separator 23, and therefore the battery element 20 includes a plurality of negative electrodes 22. Thus, the secondary battery includes a plurality of negative electrode terminals 32. The number of the negative electrode terminals 32 is not particularly limited as long as it is two or more, and thus can be arbitrarily set.
The negative electrode terminal 32 includes a conductive material such as a metal material, and the type of the conductive material is not particularly limited. Specifically, the negative electrode terminal 32 includes the same material as that of the negative electrode current collector 22A.
Here, as described above, the protruding portion of the negative electrode current collector 22A functions as the negative electrode terminal 32, and therefore, the negative electrode terminal 32 is physically integrated with the negative electrode current collector 22A. This is because the connection resistance between the negative electrode current collector 22A and the negative electrode terminal 32 decreases, and thus the resistance of the entire secondary battery decreases.
As will be described later, the plurality of negative terminals 32 are joined to each other by a joining method such as welding, and therefore, as shown in fig. 1, one linear joint portion 32Z is formed.
This is because the secondary battery has a multi-collector structure, and therefore the resistance of the entire secondary battery is reduced as compared with the case where the secondary battery includes a single positive electrode terminal and a single negative electrode terminal because the secondary battery includes a plurality of positive electrode terminals 31 and a plurality of negative electrode terminals 32. In the secondary battery having such a multi-collector structure, since the current is not concentrated and is easily dispersed, the temperature is not easily increased during charge and discharge, and thus, advantages can be obtained.
Positive electrode lead and negative electrode lead
As shown in fig. 1, the positive electrode lead 41 is connected to the joint 31Z, and led out from the inside of the outer packaging film 10. The positive electrode lead 41 includes a conductive material such as a metal material, and the type of the conductive material is not particularly limited. Specifically, the positive electrode lead 41 includes the same material as the material forming the positive electrode current collector 21A. The shape of the positive electrode lead 41 is not particularly limited, and specifically, is any of a thin plate shape, a mesh shape, and the like.
As shown in fig. 1, the negative electrode lead 42 is connected to the joint 32Z, and led out from the inside of the outer packaging film 10. The negative electrode lead 42 includes a conductive material such as a metal material, and the type of the conductive material is not particularly limited. Specifically, the negative electrode lead 42 includes the same material as that of the negative electrode current collector 22A. The lead-out direction of the negative electrode lead 42 is the same as the lead-out direction of the positive electrode lead 41. The details regarding the shape of the negative electrode lead 42 are the same as those regarding the shape of the positive electrode lead 41.
[ Sealing film ]
The sealing film 51 is interposed between the exterior film 10 and the positive electrode lead 41, and the sealing film 52 is interposed between the exterior film 10 and the negative electrode lead 42. However, one or both of the sealing films 51 and 52 may be omitted.
The sealing film 51 is a sealing member for preventing external air or the like from entering the inside of the outer packaging film 10. The sealing film 51 contains a polymer compound such as polyolefin, which has adhesion to the positive electrode lead 41, and a specific example of the polyolefin is polypropylene.
The sealing film 52 has the same structure as the sealing film 51 except that it is a sealing member having adhesion to the negative electrode lead 42. That is, the sealing film 52 contains a polymer compound such as polyolefin having adhesion to the negative electrode lead 42.
< 1-2 Action >
When the secondary battery is charged, lithium is extracted from the positive electrode 21 in the battery element 20, and the lithium is extracted into the negative electrode 22 via the electrolyte. On the other hand, at the time of discharging the secondary battery, lithium is extracted from the negative electrode 22 in the battery element 20, and the lithium is extracted into the positive electrode 21 via the electrolyte. Lithium is intercalated and deintercalated in an ionic state during these charging and discharging.
< 1-3. Manufacturing method >
Fig. 5 is a perspective view corresponding to fig. 1 for explaining a method of manufacturing a secondary battery. However, fig. 5 shows a laminate 20Z for manufacturing the battery element 20 instead of the battery element 20. Further, details of the laminated body 20Z will be described below.
In the case of manufacturing a secondary battery, the positive electrode 21 and the negative electrode 22 are manufactured by the steps of an example described below, respectively, and after the electrolyte is prepared, the secondary battery is assembled using the positive electrode 21, the negative electrode 22, and the electrolyte, and stabilization treatment of the secondary battery is performed.
[ Production of Positive electrode ]
First, a mixture (positive electrode mixture) of a positive electrode active material, a positive electrode binder, and a positive electrode conductive agent mixed with each other is put into a solvent to prepare a paste-like positive electrode mixture slurry. The solvent may be an aqueous solvent or an organic solvent. Next, the positive electrode active material layer 21B is formed by applying a positive electrode mixture slurry to both surfaces of the positive electrode current collector 21A (except for the positive electrode terminal 31) to which the positive electrode terminal 31 is integrated. Finally, the positive electrode active material layer 21B is compression-molded using a roll press or the like. In this case, the positive electrode active material layer 21B may be heated, or compression molding may be repeated a plurality of times. Thus, the positive electrode 21 is produced by forming the positive electrode active material layer 21B on both sides of the positive electrode current collector 21A.
[ Production of negative electrode ]
The negative electrode 22 is formed by the same steps as those for manufacturing the positive electrode 21 described above. Specifically, first, a mixture (negative electrode mixture) of a negative electrode active material, a negative electrode binder, and a negative electrode conductive agent, which are mixed with each other, is put into a solvent to prepare a paste-like negative electrode mixture slurry. Details regarding the solvent are as described above. Next, the negative electrode mixture paste is applied to both surfaces of the negative electrode current collector 22A integrated with the negative electrode terminal 32 (except for the negative electrode terminal 32), thereby forming the negative electrode active material layer 22B. Finally, the negative electrode active material layer 22B is compression-molded. Thus, the anode 22 is produced by forming the anode active material layer 22B on both sides of the anode current collector 22A.
[ Preparation of electrolyte ]
An electrolyte salt containing imide anions is put into a solvent. In this case, other electrolyte salts may be further added to the solvent, or additives may be further added to the solvent. Thus, an electrolyte salt or the like is dispersed or dissolved in a solvent, and thus an electrolyte solution is prepared.
[ Assembly of Secondary Battery ]
First, the positive electrode 21 and the negative electrode 22 are alternately laminated through the separator 23, whereby a laminate 20Z is produced as shown in fig. 5. The laminate 20Z has the same structure as the battery element 20 except that the electrolyte is not impregnated in each of the positive electrode 21, the negative electrode 22, and the separator 23.
Next, the plurality of positive electrode terminals 31 are bonded to each other by a bonding method such as welding to form a bonding portion 31Z, and then the positive electrode lead 41 is connected to the bonding portion 31Z by a bonding method such as welding. The plurality of negative electrode terminals 32 are joined to each other by a joining method such as welding to form a joint portion 32Z, and then the negative electrode lead 42 is connected to the joint portion 32Z by a joining method such as welding.
Next, after the laminate 20Z is accommodated in the recess 10U, the outer packaging film 10 (fusion layer/metal layer/surface protection layer) is folded, whereby the outer packaging films 10 are opposed to each other. Next, the outer peripheral edge portions of the two sides of the welding layer facing each other are bonded to each other by using an adhesion method such as a heat welding method, whereby the laminate 20Z is housed inside the bag-like outer packaging film 10.
Finally, after the electrolyte is injected into the bag-shaped outer packaging film 10, the outer peripheral edge portions of the remaining one of the mutually opposing fusion-bonding layers are bonded to each other by a bonding method such as a hot-melt bonding method. In this case, the sealing film 51 is interposed between the exterior film 10 and the positive electrode lead 41, and the sealing film 52 is interposed between the exterior film 10 and the negative electrode lead 42.
Thus, the electrolyte is impregnated into the laminate 20Z, and thus the battery element 20 as a laminated electrode body is produced. Thus, the battery element 20 is sealed inside the pouch-shaped exterior film 10, and the secondary battery is assembled.
[ Stabilization of Secondary Battery ]
And charging and discharging the assembled secondary battery. The ambient temperature, the number of charge/discharge cycles (the number of cycles), and various conditions such as charge/discharge conditions can be arbitrarily set. As a result, a coating film is formed on the surface of each of the positive electrode 21 and the negative electrode 22, and thus the state of the secondary battery is electrochemically stabilized. Thereby, the secondary battery is completed.
< 1-4 Actions and effects >
According to this secondary battery, the plurality of positive electrode terminals 31 are electrically connected to the positive electrode 21, the plurality of negative electrode terminals 32 are electrically connected to the negative electrode 22, and the electrolyte salt of the electrolytic solution contains any one or two or more anions represented by each of the formulas (1) to (4) as imide anions. This can provide excellent battery characteristics for the reasons described below.
Fig. 6 shows a three-dimensional structure of the secondary battery of the comparative example, corresponding to fig. 1. The secondary battery of this comparative example has the same structure as the secondary battery of the present embodiment (fig. 1 to 4) except for the matters described below.
As shown in fig. 6, the secondary battery of the comparative example has a so-called single current collection structure unlike the secondary battery of the present embodiment, and therefore does not have a multi-current collection structure.
Specifically, the secondary battery of the comparative example includes a battery element 60 as a wound electrode body instead of the battery element 20 as a laminated electrode body, and the battery element 60 includes a positive electrode 21, a negative electrode 22, and a separator 23, similarly to the battery element 20. Further, a part (protruding portion) of the positive electrode collector 21A functions as the positive electrode terminal 31, and a part (protruding portion) of the negative electrode collector 22A functions as the negative electrode terminal 32.
However, the positive electrode 21 has a belt-like structure extending in a direction (X-axis direction) intersecting the protruding direction (Y-axis direction) of the positive electrode terminal 31, and the negative electrode 22 has a belt-like structure extending in a direction (X-axis direction) intersecting the protruding direction (Y-axis direction) of the negative electrode terminal 32. Thus, the battery element 60 includes the single positive electrode 21, the single negative electrode 22, and the single separator 23, and the positive electrode 21 and the negative electrode 22 are wound around the winding axis P while facing each other through the separator 23. The winding axis P is a virtual axis extending in the Y-axis direction.
The three-dimensional shape of the battery element 60 is not particularly limited. Here, since the battery element 60 is flat, the cross section (cross section along the XZ plane) of the battery element 60 intersecting the winding axis P has a flat shape defined by the major axis J1 and the minor axis J2. The long axis J1 is an imaginary axis extending in the X-axis direction and having a length greater than the short axis J2, and the short axis J2 is an imaginary axis extending in the Z-axis direction intersecting the X-axis direction and having a length smaller than the long axis J1. Here, the three-dimensional shape of the battery element 60 is a flat cylindrical shape, and therefore, the cross-sectional shape of the battery element 60 is a flat substantially elliptical shape.
Further, the secondary battery of the comparative example includes a single positive electrode terminal 31 and a single negative electrode terminal 32, and therefore does not include the joint portions 31Z, 32Z. Thus, a single positive terminal 31 is electrically connected to the positive electrode 21, and a single negative terminal 32 is electrically connected to the negative electrode 22. Further, the positive electrode lead 41 is connected to the single positive electrode terminal 31, and the negative electrode lead 42 is connected to the single negative electrode terminal 32.
The method for manufacturing the secondary battery of the comparative example is the same as the method for manufacturing the secondary battery of the present embodiment except for the matters described below.
In the case where the secondary battery is to be assembled, a single positive electrode 21 in which the positive electrode terminal 31 is integrated with the positive electrode collector 21A is used, and a single negative electrode 22 in which the negative electrode terminal 32 is integrated with the negative electrode collector 22A is used. Thus, the positive electrode lead 41 is connected to the positive electrode terminal 31, and the negative electrode lead 42 is connected to the negative electrode terminal 32, and then the positive electrode 21 and the negative electrode 22 are wound while facing each other through the separator 23, thereby producing a wound body (not shown). The wound body has the same structure as that of the battery element 60, except that the electrolyte is not impregnated in each of the positive electrode 21, the negative electrode 22, and the separator 23. Then, the wound body is housed inside the bag-shaped outer packaging film 10.
In the case where the electrolyte salt of the electrolytic solution contains an imide anion, as described above, a high-quality coating film from the electrolyte salt is formed on the surface of each of the positive electrode 21 and the negative electrode 22 at the time of charge and discharge, and therefore decomposition of the electrolytic solution is suppressed. In addition, in the vicinity of the surface of each of the positive electrode 21 and the negative electrode 22, the movement speed of the cations is increased, and in the liquid of the electrolytic solution, the movement speed of the cations is also increased.
However, the secondary battery of the comparative example has a single current collecting structure, and thus the resistance of the entire secondary battery increases.
In contrast, the secondary battery of the present embodiment has a multi-collector structure, and therefore, as described above, the resistance of the entire secondary battery decreases.
Thus, in the secondary battery using the electrolyte, excellent battery characteristics can be obtained.
In particular, if the electrolyte salt contains a light metal ion as a cation, a high voltage is obtained, and thus a higher effect can be obtained. In this case, if the light metal ions include lithium ions, a higher voltage is obtained, and thus a further higher effect can be obtained.
Further, if the content of the electrolyte salt in the electrolyte is 0.2mol/kg to 2mol/kg, high ion conductivity is obtained, and thus a higher effect can be obtained.
Further, if the electrolyte further contains any one or two or more of unsaturated cyclic carbonate, fluorinated cyclic carbonate, sulfonate, dicarboxylic anhydride, disulfonic anhydride, sulfate, nitrile compound, and isocyanate compound as an additive, the decomposition reaction of the electrolyte is suppressed, and thus a higher effect can be obtained.
Further, if the electrolyte solution further contains any one or two or more of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis (fluorosulfonyl) imide, lithium bis (oxalato) borate, and lithium difluorophosphate as other electrolyte salts, the movement speed of lithium ions is further improved, and thus a higher effect can be obtained.
Further, if the secondary battery is a lithium ion secondary battery, a sufficient battery capacity is stably obtained by intercalation and deintercalation of lithium, and thus a higher effect can be obtained.
< 2. Modification >
The structure of the secondary battery described above can be appropriately modified as described below. However, a series of modifications described below may be combined with each other.
Modification 1
In fig. 3, the protruding portion of the positive electrode collector 21A doubles as the positive electrode terminal 31, and therefore the positive electrode terminal 31 is physically integrated with the positive electrode collector 21A. However, the positive electrode terminal 31 may be physically separated from the positive electrode current collector 21A, and thus may be separated from the positive electrode current collector 21A. In this case, the positive electrode terminal 31 may be connected to the positive electrode current collector 21A by a bonding method such as welding.
In this case, the positive electrode terminal 31 is electrically connected to the positive electrode 21, and therefore the same effect can be obtained. However, as described above, in order to reduce the resistance of the entire secondary battery in response to the reduction in the connection resistance, the positive electrode terminal 31 is preferably physically integrated with the positive electrode current collector 21A.
Also, in fig. 4, the protruding portion of the negative electrode current collector 22A doubles as the negative electrode terminal 32, and therefore the negative electrode terminal 32 is physically integrated with the negative electrode current collector 22A. However, the negative electrode terminal 32 may be physically separated from the negative electrode current collector 22A, and thus may be separated from the negative electrode current collector 22A. In this case, the negative electrode terminal 32 may be connected to the negative electrode current collector 22A by a bonding method such as welding.
In this case, the negative electrode terminal 32 is electrically connected to the negative electrode 22, and therefore the same effect can be obtained. However, as described above, in order to reduce the resistance of the entire secondary battery in response to the reduction in the connection resistance, the negative electrode terminal 32 is preferably physically integrated with the negative electrode current collector 22A.
Modification 2
In fig. 1, a battery element 20 as a laminated electrode body is used. Although not specifically illustrated here, a battery element as a wound electrode body may be used. In this case, the positive electrode 21 has a belt-like structure, the plurality of positive electrode terminals 31 are electrically connected to the positive electrode current collector 21A, and the negative electrode 22 has a belt-like structure, and the plurality of negative electrode terminals 32 are electrically connected to the negative electrode current collector 22A. Thus, the positive electrode 21 and the negative electrode 22 are wound while facing each other via the separator 23.
In this case, the secondary battery having a multi-collector structure is realized, and therefore the same effects can be obtained.
Modification 3
As described above, the electrolyte solution may also contain an electrolyte salt containing imide anions and other electrolyte salts.
Among these, it is preferable that the electrolyte contains lithium hexafluorophosphate as another electrolyte salt, and the content of the electrolyte salt in the electrolyte is appropriately adjusted in relation to the content of lithium hexafluorophosphate in the electrolyte.
Specifically, the electrolyte salt contains a cation and an imide anion. In addition, the hexafluorophosphate ion contains lithium ion and hexafluorophosphate ion.
In this case, the sum T (mol/kg) of the cation content C1 in the electrolyte and the lithium ion content C2 in the electrolyte is preferably 0.7mol/kg to 2.2mol/kg. The ratio R (mol%) of the molar number M2 of hexafluorophosphate ions in the electrolyte is preferably 13mol% to 6000mol% with respect to the molar number M1 of imide anions in the electrolyte. This is because the movement speed of each of the cations and lithium ions is sufficiently increased near the surface of each of the positive electrode 21 and the negative electrode 22, and the movement speed of each of the cations and lithium ions is also sufficiently increased in the liquid of the electrolyte.
The "content of cations in the electrolyte" described herein is the content of cations with respect to the solvent, and the "content of lithium ions in the electrolyte" is the content of lithium ions with respect to the solvent. Further, the sum T is calculated based on a calculation formula of t=c1+c2, and the ratio R is calculated based on a calculation formula of r= (M2/M1) ×100.
In the case where each of the sum T and the ratio R is to be calculated, the electrolyte is recovered by disassembling the secondary battery, and then analyzed using ICP emission spectrometry. Thus, each of the contents C1, C2 and the numbers of moles M1, M2 is determined, and each of the sum T and the ratio R is calculated therefrom.
In this case, the electrolyte solution also contains an electrolyte salt, and thus the same effects can be obtained. In this case, in particular, in the case where an electrolyte salt and another electrolyte salt (lithium hexafluorophosphate) are used in combination, the total amount (sum T) of both is appropriately adjusted, and the mixing ratio (ratio R) of both is appropriately adjusted. Thereby, in the vicinity of the surface of each of the positive electrode 21 and the negative electrode 22, the movement speed of each of the cations and the lithium ions is further increased, and in the liquid of the electrolytic solution, the movement speed of each of the cations and the lithium ions is also further increased. This can obtain a higher effect.
Modification 4
A separator 23 is used as a porous membrane. However, although not specifically shown here, a laminated separator including a polymer compound layer may be used.
Specifically, the laminated separator includes a porous film having a pair of surfaces and a polymer compound layer provided on one or both surfaces of the porous film. This is because the separator has improved adhesion to each of the positive electrode 21 and the negative electrode 22, and therefore, positional displacement (winding displacement) of the battery element 20 is suppressed. This suppresses swelling of the secondary battery even when a side reaction such as a decomposition reaction of the electrolyte occurs. The polymer compound layer contains a polymer compound such as polyvinylidene fluoride. This is because excellent physical strength and excellent electrochemical stability are obtained.
One or both of the porous film and the polymer compound layer may contain any one or two or more of a plurality of insulating particles. This is because the plurality of insulating particles promote heat dissipation when the secondary battery generates heat, and therefore the safety (heat resistance) of the secondary battery is improved. The insulating particles contain one or both of an inorganic material and a resin material. Specific examples of the inorganic material are alumina, aluminum nitride, boehmite, silica, titania, magnesia, zirconia, and the like. Specific examples of the resin material are acrylic resin, styrene resin, and the like.
In the case of producing a laminated separator, a precursor solution containing a polymer compound, a solvent, and the like is prepared, and then the precursor solution is applied to one or both surfaces of the porous film. In this case, a plurality of insulating particles may be added to the precursor solution as needed.
Even when this laminated separator is used, lithium ions can move between the positive electrode 21 and the negative electrode 22, and therefore the same effect can be obtained. In this case, in particular, as described above, the safety of the secondary battery is improved, and thus a higher effect can be obtained.
Modification 5
An electrolyte solution is used as a liquid electrolyte. However, although not specifically shown here, an electrolyte layer may be used as a gel-like electrolyte.
In the battery element 20 using the electrolyte layer, the positive electrode 21 and the negative electrode 22 are stacked on each other via the separator 23 and the electrolyte layer, and the positive electrode 21, the negative electrode 22, the separator 23, and the electrolyte layer are wound. The electrolyte layer is interposed between the positive electrode 21 and the separator 23, and between the negative electrode 22 and the separator 23.
Specifically, the electrolyte layer contains an electrolyte solution and a polymer compound, and the electrolyte solution is held by the polymer compound. This is because leakage of the electrolyte is prevented. The electrolyte is constructed as described above. The polymer compound includes polyvinylidene fluoride and the like. In the case where an electrolyte layer is to be formed, after preparing a precursor solution containing an electrolyte solution, a polymer compound, a solvent, and the like, the precursor solution is coated on one side or both sides of each of the positive electrode 21 and the negative electrode 22.
Even when this electrolyte layer is used, lithium ions can move between the positive electrode 21 and the negative electrode 22 through the electrolyte layer, and therefore the same effect can be obtained. In this case, in particular, as described above, leakage of the electrolyte is prevented, and thus a higher effect can be obtained.
< 3 Use of Secondary Battery >
The use (application example) of the secondary battery is not particularly limited. The secondary battery used as a power source may be a main power source of an electronic device, an electric vehicle, or the like, or may be an auxiliary power source. The main power supply is a power supply that is preferentially used regardless of the presence or absence of other power supplies. The auxiliary power supply is a power supply used in place of the main power supply or a power supply switched from the main power supply.
Specific examples of the use of the secondary battery are as follows: electronic devices such as video cameras, digital still cameras, mobile phones, notebook computers, stereo headphones, portable radios, and portable information terminals; a backup power supply and a storage device such as a memory card; electric drill and electric saw; a battery pack mounted on an electronic device or the like; medical electronic devices such as pacemakers and hearing aids; electric vehicles such as electric vehicles (including hybrid vehicles); an electric power storage system such as a battery system for household or industrial use, which stores electric power in advance in response to an emergency. In these applications, one secondary battery may be used, or a plurality of secondary batteries may be used.
The battery pack may use a single cell or a battery pack. The electric vehicle is a vehicle that operates (travels) using a secondary battery as a driving power source, and may be a hybrid vehicle that includes other driving sources other than the secondary battery. In a household electric power storage system, household electric appliances and the like can be used by using electric power stored in a secondary battery as an electric power storage source.
Here, an example of an application example of the secondary battery will be specifically described. The configuration of the application examples described below is merely an example, and can be changed as appropriate.
Fig. 7 shows a module structure of the battery pack. The battery pack described here is a battery pack (so-called soft pack) using one secondary battery, and is mounted on an electronic device typified by a smart phone.
As shown in fig. 7, the battery pack includes a power supply 71 and a circuit board 72. The circuit board 72 is connected to the power supply 71, and includes a positive electrode terminal 73, a negative electrode terminal 74, and a temperature detection terminal 75.
The power supply 71 includes a secondary battery. In this secondary battery, a positive electrode lead is connected to a positive electrode terminal 73, and a negative electrode lead is connected to a negative electrode terminal 74. The power supply 71 can be connected to the outside via the positive electrode terminal 73 and the negative electrode terminal 74, and thus can be charged and discharged. The circuit substrate 72 includes a control portion 76, a switch 77, a PTC element 78, and a temperature detecting portion 79. The PTC element 78 may be omitted.
The control unit 76 includes a Central Processing Unit (CPU), a memory, and the like, and controls the operation of the entire battery pack. The control unit 76 detects and controls the use state of the power supply 71 as needed.
In addition, if the voltage of the power source 71 (secondary battery) reaches the overcharge detection voltage or the overdischarge detection voltage, the control section 76 turns off the switch 77, and the charging current does not flow through the current path of the power source 71. The overcharge detection voltage is not particularly limited, specifically, 4.20v±0.05V, and the overdischarge detection voltage is not particularly limited, specifically, 2.40v±0.1V.
The switch 77 includes a charge control switch, a discharge control switch, a charge diode, a discharge diode, and the like, and switches whether or not the power supply 71 is connected to an external device according to an instruction from the control unit 76. The switch 77 includes a field effect transistor (MOSFET) or the like using a metal oxide semiconductor, and the charge-discharge current is detected based on the on-resistance of the switch 77.
The temperature detection unit 79 includes a temperature detection element such as a thermistor, measures the temperature of the power supply 71 using the temperature detection terminal 75, and outputs the measurement result of the temperature to the control unit 76. The measurement result of the temperature measured by the temperature detecting unit 79 is used for the case where the control unit 76 performs charge/discharge control during abnormal heat generation, the case where the control unit 76 performs correction processing during calculation of the remaining capacity, and the like.
[ Example ]
Embodiments of the present technology are described.
Examples 1 to 10 and comparative examples 1 to 3 >
After the secondary battery was manufactured, the battery characteristics of the secondary battery were evaluated as described below.
[ Production of Secondary Battery ]
The laminated film secondary batteries (lithium ion secondary batteries) shown in fig. 1 to 4 were produced by the following steps.
(Preparation of positive electrode)
First, 91 parts by mass of a positive electrode active material (LiNi 0.82Co0.14Al0.04O2 as a lithium-containing compound (oxide)), 3 parts by mass of a positive electrode binder (polyvinylidene fluoride), and 6 parts by mass of a positive electrode conductive agent (carbon black) were mixed with each other to prepare a positive electrode mixture. Next, after the positive electrode mixture is put into a solvent (N-methyl-2-pyrrolidone as an organic solvent), the organic solvent is stirred, whereby a paste-like positive electrode mixture slurry is prepared. Next, a positive electrode mixture slurry was applied to both surfaces (except for the positive electrode terminal 31) of the positive electrode current collector 21A (a band-shaped aluminum foil having a thickness=12 μm) in which the positive electrode terminal 31 (aluminum foil) was integrated using a coating apparatus, and then the positive electrode mixture slurry was dried, thereby forming the positive electrode active material layer 21B. Finally, the positive electrode active material layer 21B is compression-molded using a roll press. Thus, the positive electrode 21 was produced.
(Production of negative electrode)
First, 93 parts by mass of a negative electrode active material (artificial graphite as a carbon material, surface interval of (002) plane measured by X-ray diffraction method= 0.3358 nm) and 7 parts by mass of a negative electrode binder (styrene-butadiene rubber) were mixed with each other to prepare a negative electrode mixture. Next, after the negative electrode mixture is put into a solvent (water as an aqueous solvent), the organic solvent is stirred, thereby preparing a paste-like negative electrode mixture slurry. Next, a negative electrode mixture paste was applied to both sides (except for the negative electrode terminal 32) of the negative electrode current collector 22A (a strip-shaped copper foil having a thickness=15 μm) integrated with the negative electrode terminal 32 (copper foil) using an applicator, and then the negative electrode mixture paste was dried, thereby forming the negative electrode active material layer 22B. Finally, the negative electrode active material layer 22B is compression-molded using a roll press. Thus, the negative electrode 22 was produced.
(Preparation of electrolyte)
First, after the electrolyte salt is put into a solvent, the solvent is stirred.
As the solvent, ethylene carbonate as a cyclic carbonate and γ -butyrolactone as a lactone were used. In this case, the mixing ratio (weight ratio) of the solvents was set to ethylene carbonate: γ -butyrolactone = 30:70.
As the cations of the electrolyte salt, lithium ions (Li +) are used. As the anion of the electrolyte salt, a first imide anion represented by each of the formulas (1-5), (1-6), (1-21) and (1-22), a second imide anion represented by the formula (2-5), a third imide anion represented by the formula (3-5) and a fourth imide anion represented by the formula (4-37) are used. The electrolyte salt content (mol/kg) is shown in Table 1.
Thereby, an electrolyte solution containing an electrolyte salt is prepared. The electrolyte salt is a lithium salt containing an imide anion as an anion.
In addition, as shown in table 1, for comparison, an electrolyte was prepared by the same procedure except that hexafluorophosphate ion (PF 6 -) was used instead of imide anion as anion.
(Assembly of Secondary Battery)
First, the positive electrode 21 and the negative electrode 22 were laminated to each other via the separator 23 (microporous polyethylene film having a thickness=15 μm), thereby producing a laminate 20Z.
Next, the plurality of positive electrode terminals 31 are welded to each other to form a joint 31Z, and then the positive electrode lead 41 (aluminum foil) is welded to the joint 31Z. Further, by welding the plurality of negative electrode terminals 32 to each other, the joint portion 32Z is formed, and then the negative electrode lead 42 (copper foil) is welded to the joint portion 32Z.
Next, after the outer packaging film 10 (weld layer/metal layer/surface protective layer) is folded so as to sandwich the laminate 20Z accommodated in the recess 10U, the outer peripheral edge portions of both sides of the weld layer are thermally welded to each other, whereby the laminate 20Z is accommodated in the interior of the bag-like outer packaging film 10. As the exterior film 10, an aluminum laminate film in which a welded layer (polypropylene film having a thickness of=30 μm), a metal layer (aluminum foil having a thickness of=40 μm), and a surface protective layer (nylon film having a thickness of=25 μm) were laminated in this order from the inside was used.
Finally, after the electrolyte is injected into the bag-shaped outer packaging film 10, the outer peripheral edge portions of the remaining one of the weld layers are thermally welded to each other in a reduced pressure environment. In this case, the sealing film 51 (polypropylene film having a thickness=5 μm) is interposed between the exterior packaging film 10 and the positive electrode lead 41, and the sealing film 52 (polypropylene film having a thickness=5 μm) is interposed between the exterior packaging film 10 and the negative electrode lead 42. Thus, the electrolyte is impregnated into the laminate 20Z, and thus the battery element 20 as a laminated electrode body is produced.
Thus, the battery element 20 is sealed inside the exterior film 10, and the secondary battery is assembled.
As shown in table 1, the secondary battery shown in fig. 6 was assembled by the same procedure except that the battery element 60 as the wound electrode body was fabricated instead of the battery element 20 as the laminated electrode body for comparison. In this case, the positive electrode 21 and the negative electrode 22 are wound while being opposed to each other via the separator 23, whereby a wound body is produced, and then the wound body is housed in the bag-shaped outer packaging film 10.
In table 1, the column "current collecting structure" indicates the structure of the secondary battery. Specifically, "multi-collector" means that a secondary battery (fig. 1) including a battery element 20 as a laminated electrode body, a plurality of positive electrode terminals 31, and a plurality of negative electrode terminals 32 is assembled. Further, "single collector" means that the assembly of the battery element 60 as a wound electrode body and the secondary battery (fig. 6) of the single positive electrode terminal 31 and the single negative electrode terminal 32 is performed.
(Stabilization of Secondary Battery)
In a normal temperature environment (temperature=23℃), the secondary battery was charged and discharged in 1 cycle. At the time of charging, after constant current charging was performed at a current of 0.1C until the voltage reached 4.1V, constant voltage charging was performed at the voltage of 4.1V until the current reached 0.05C. At the time of discharge, constant current discharge was performed at a current of 0.1C until the voltage reached 2.5V.0.1C means a current value at which the battery capacity (theoretical capacity) is completely discharged within 10 hours, and 0.05C means a current value at which the battery capacity is completely discharged within 20 hours.
As a result, a coating film is formed on the surface of each of the positive electrode 21 and the negative electrode 22, and thus the state of the secondary battery is electrochemically stabilized. Thus, a laminate film type secondary battery was completed.
In addition, after the secondary battery is completed, the electrolyte is analyzed using an inductively coupled high-frequency plasma (Inductively Coupled Plasma (ICP)) emission spectrometry. As a result, the types and contents (mol/kg) of the electrolyte salts (cations and anions) were confirmed as shown in table 1.
[ Evaluation of Battery characteristics ]
The battery characteristics were evaluated, and the results shown in table 1 were obtained. Here, the high temperature cycle characteristics, the high temperature storage characteristics, and the low temperature load characteristics were evaluated.
(High temperature cycle characteristics)
First, the secondary battery was charged and discharged in a high-temperature environment (temperature=60℃), whereby the discharge capacity (discharge capacity of 1 st cycle) was measured. The charge and discharge conditions are the same as those in the stabilization of the secondary battery described above.
Next, in the same environment, the secondary battery was repeatedly charged and discharged until the total number of cycles reached 100 cycles, whereby the discharge capacity (discharge capacity at the 100 th cycle) was measured. The charge and discharge conditions are the same as those in the stabilization of the secondary battery described above.
Finally, the cycle maintenance rate, which is an index for evaluating the high-temperature cycle characteristics, is calculated based on a calculation formula of cycle maintenance rate (%) = (discharge capacity of the 100 th cycle/discharge capacity of the 1 st cycle) ×100.
(High temperature preservation Property)
First, in a normal temperature environment (temperature=23℃), the discharge capacity (discharge capacity before storage) was measured by charging and discharging the secondary battery in 1 cycle. The charge and discharge conditions are the same as those in the stabilization of the secondary battery described above.
Next, the secondary battery was charged in the same environment, and the charged secondary battery was stored in a high-temperature environment (temperature=80℃) (storage time=10 days), and then discharged in a normal-temperature environment, whereby the discharge capacity (discharge capacity after storage) was measured. The charge and discharge conditions are the same as those in the stabilization of the secondary battery described above.
Finally, the storage maintenance rate, which is an index for evaluating the high-temperature storage characteristics, is calculated based on a calculation formula of storage maintenance rate (%) = (discharge capacity after storage/discharge capacity before storage) ×100.
(Low temperature load characteristics)
First, in a normal temperature environment (temperature=23℃), the secondary battery was charged and discharged for 1 cycle, and the discharge capacity (discharge capacity for the 1 st cycle) was measured. The charge and discharge conditions are the same as those in the stabilization of the secondary battery described above.
Next, the secondary battery was repeatedly charged and discharged in a low-temperature environment (temperature= -10 ℃) until the total number of cycles reached 100 cycles, and the discharge capacity (discharge capacity of the 100 th cycle) was measured. The charge and discharge conditions were the same as those in the stabilization of the secondary battery described above, except that the current at the time of discharge was changed to 1C. 1C is a current value at which the battery capacity is completely discharged within 1 hour.
Finally, the load maintenance rate, which is an index for evaluating the low-temperature load characteristics, is calculated based on a calculation formula of load maintenance rate (%) = (discharge capacity of the 100 th cycle/discharge capacity of the 1 st cycle) ×100.
[ Inspection ]
As shown in table 1, the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate vary greatly depending on the structure of the secondary battery.
Specifically, in the case where the electrolyte salt does not contain an imide anion in the secondary battery of a single current collector (comparative example 1), the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate are reduced.
In the case where the electrolyte salt does not contain an imide anion in the multi-collector secondary battery (comparative example 2), the load maintenance rate is slightly increased as compared with the case where the electrolyte salt does not contain an imide anion in the single-collector secondary battery (comparative example 1), but the cycle maintenance rate and the storage maintenance rate are equivalent, respectively.
Further, in the case where the electrolyte salt contains an imide anion in the single-collector secondary battery (comparative example 3), the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate are each increased, but the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate are not sufficiently increased, respectively, as compared with the case where the electrolyte solution does not contain an imide anion in the single-collector secondary battery (comparative example 1).
In contrast, when the electrolyte salt contained an imide anion in the multi-collector secondary battery (examples 1 to 10), a high cycle maintenance rate, a high storage maintenance rate, and a high load maintenance rate were obtained. That is, in the case where the electrolyte salt contains an imide anion in the multi-collector secondary battery (example 3), the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate are each significantly increased as compared to the case where the electrolyte salt does not contain an imide anion in the single-collector secondary battery (comparative example 1).
In this case (examples 1 to 10), the following tendency is particularly obtained. First, if the electrolyte salt contains a light metal ion (lithium ion) as a cation, the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate become sufficiently high, respectively. Second, if the content of the electrolyte salt is 0.2mol/kg to 2mol/kg with respect to the solvent, the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate become sufficiently high, respectively.
Examples 11 to 28 >
As shown in table 2 and table 3, secondary batteries were fabricated by the same procedure as in example 3, except that any one of additives and other electrolyte salts was added to the electrolyte solution, and then the battery characteristics were evaluated.
Details regarding the additives are as described below. As the unsaturated cyclic carbonate, vinylene Carbonate (VC), vinyl Ethylene Carbonate (VEC), and Methylene Ethylene Carbonate (MEC) are used. As the fluorinated cyclic carbonate, ethylene monofluorocarbonate (FEC) and ethylene Difluorocarbonate (DFEC) were used. As the sulfonate, propane Sultone (PS) and propane sultone (PRS (propene sultone)) as cyclic monosulfonate, and ethylene glycol methyldisulfonate (CD) as cyclic disulfonate are used. As dicarboxylic anhydride, succinic Anhydride (SA) was used. As disulfonic anhydride, propane disulfonic anhydride (PSAH) was used. As the sulfate ester, vinyl sulfate (DTD) was used. As the nitrile compound, succinonitrile (SN) is used. As the isocyanate compound, hexamethylene diisocyanate (HMI) was used.
As other electrolyte salts, lithium hexafluorophosphate (LiPF 6), lithium tetrafluoroborate (LiBF 4), lithium bis (fluorosulfonyl) imide (LiFSI), lithium bis (oxalato) borate (LiBOB), and lithium difluorophosphate (LiPF 2O2) are used.
The contents (wt%) of each of the additives and other electrolyte salts in the electrolytic solution are shown in table 2 and table 3. In this case, after the completion of the secondary battery, the electrolyte was analyzed by using ICP emission spectrometry, and it was confirmed that the content of each of the additives and other electrolyte salts was as shown in table 2 and table 3.
As shown in table 1 and table 2, when the electrolyte contains the additive (examples 11 to 23), one or more of the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate is increased as compared with the case where the electrolyte does not contain the additive (example 3).
As shown in table 1 and table 3, when the electrolyte contains another electrolyte salt (examples 24 to 28), one or more of the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate increases as compared with the case where the electrolyte does not contain another electrolyte salt (example 3).
Examples 29 to 60 >
As shown in table 4 and table 5, secondary batteries were produced by the same procedure as in example 3, except that the electrolyte solution was made to contain other electrolyte salts (lithium hexafluorophosphate (LiPF 6)), and then the battery characteristics were evaluated.
In this case, after the electrolyte salt and other electrolyte salts are added to the solvent, the solvent is stirred. The content (mol/kg) of the electrolyte salt, the content (mol/kg) of the other electrolyte salt, and T (mol/kg), and the ratio R (mol%) are shown in Table 4 and Table 5.
As shown in table 4 and table 5, when the conditions that the sum T is 0.7mol/kg to 2.2mol/kg and the ratio R is 13mol% to 6000mol% are satisfied (example 33 and the like), the cycle maintenance rate, the storage maintenance rate, and the load maintenance rate are each increased as compared with the case where the conditions are not satisfied (example 29 and the like).
[ Summary ]
As is clear from the results shown in tables 1 to 5, if the plurality of positive electrode terminals 31 are electrically connected to the positive electrode 21 and the plurality of negative electrode terminals 32 are electrically connected to the negative electrode 22, the electrolyte salt of the electrolytic solution contains any one or two or more of the anions shown in each of the formulas (1) to (4) as the imide anion, and the cycle maintenance rate, the storage maintenance rate and the load maintenance rate are improved. In this way, in the secondary battery, excellent high-temperature cycle characteristics, excellent high-temperature storage characteristics, and excellent low-temperature load characteristics are obtained, and therefore excellent battery characteristics can be obtained.
The present technology has been described above with reference to one embodiment and example, but the configuration of the present technology is not limited to the configuration described in the one embodiment and example, and thus various modifications are possible.
Specifically, a case where the element structure of the battery element is a laminated type (laminated electrode body) and a wound type (wound electrode body) will be described. However, the element structure of the battery element is not particularly limited as long as a multi-collector structure is ensured, and may be a meandering structure or the like. In the zigzag type, the positive electrode and the negative electrode are folded in a zigzag shape while facing each other via the separator.
The case where the electrode reaction material is lithium is described, but the electrode reaction material is not particularly limited. Specifically, as described above, the electrode reaction material may be other alkali metals such as sodium and potassium, or alkaline earth metals such as beryllium, magnesium and calcium. The electrode reaction material may be another light metal such as aluminum.
The effects described in the present specification are merely examples, and therefore the effects of the present technology are not limited to the effects described in the present specification. Thus, other effects can be obtained with the present technology.
Claims (8)
1. A secondary battery is provided with:
A positive electrode;
A negative electrode;
an electrolyte comprising an electrolyte salt;
a plurality of positive electrode terminals electrically connected to the positive electrode; and
A plurality of negative terminals electrically connected to the negative electrode,
The electrolyte salt contains an imide anion containing at least one of anions represented by each of formula (1), formula (2), formula (3) and formula (4),
Each of R1 and R2 is any one of a fluoro group and a fluoroalkyl group, each of W1, W2, and W3 is any one of a carbonyl group (> c=o), a sulfinyl group (> s=o), and a sulfonyl group (> S (=o) 2),
Each of R3 and R4 is any one of a fluoro group and a fluoroalkyl group, each of X1, X2, X3 and X4 is any one of a carbonyl group, a sulfinyl group and a sulfonyl group,
R5 is a fluoroalkylene group, each of Y1, Y2 and Y3 is any one of a carbonyl group, a sulfinyl group and a sulfonyl group,
Each of R6 and R7 is any one of fluoro and fluoroalkyl, R8 is any one of alkylene, phenylene, fluoroalkylene, and each of Z1, Z2, Z3, and Z4 is any one of carbonyl, sulfinyl, and sulfonyl.
2. The secondary battery according to claim 1, wherein,
The electrolyte salt further comprises a cation,
The cations comprise light metal ions.
3. The secondary battery according to claim 2, wherein,
The light metal ions comprise lithium ions.
4. The secondary battery according to any one of claim 1 to 3, wherein,
The electrolyte salt content in the electrolyte is 0.2mol/kg or more and 2mol/kg or less.
5. The secondary battery according to any one of claim 1 to 3, wherein,
The electrolyte further comprises lithium hexafluorophosphate,
The electrolyte salt comprises a cation and the imide anion,
The lithium hexafluorophosphate comprises lithium ions and hexafluorophosphate ions,
The sum of the content of the cations in the electrolyte and the content of the lithium ions in the electrolyte is 0.7mol/kg or more and 2.2mol/kg or less,
The ratio of the number of moles of the hexafluorophosphate ion in the electrolyte to the number of moles of the imide anion in the electrolyte is 13mol% or more and 6000mol% or less.
6. The secondary battery according to any one of claims 1 to 5, wherein,
The electrolyte further contains at least one of an unsaturated cyclic carbonate, a fluorinated cyclic carbonate, a sulfonate, a dicarboxylic anhydride, a disulfonic anhydride, a sulfate, a nitrile compound, and an isocyanate compound.
7. The secondary battery according to any one of claims 1 to 6, wherein,
The electrolyte further comprises at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis (fluorosulfonyl) imide, lithium bis (oxalato) borate, and lithium difluorophosphate.
8. The secondary battery according to any one of claims 1 to 7, wherein,
The secondary battery is a lithium ion secondary battery.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022028428 | 2022-02-25 | ||
| JP2022-028428 | 2022-02-25 | ||
| PCT/JP2022/046845 WO2023162432A1 (en) | 2022-02-25 | 2022-12-20 | Secondary battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118451580A true CN118451580A (en) | 2024-08-06 |
Family
ID=87765548
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280086003.4A Pending CN118451580A (en) | 2022-02-25 | 2022-12-20 | Secondary battery |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN118451580A (en) |
| WO (1) | WO2023162432A1 (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19733948A1 (en) * | 1997-08-06 | 1999-02-11 | Merck Patent Gmbh | Process for the preparation of perfluoroalkane-1-sulfonyl (perfluoroalkylsulfonyl) imide-N-sulfonyl-containing methanides, imides and sulfonates, and perfluoroalkane-1-N- (sulfonylbis (perfluoroalkylsulfonyl) methanides) |
| CN103563155B (en) * | 2011-06-07 | 2017-07-21 | 3M创新有限公司 | Include the lithium ion electrochemical cells of fluorocarbon additive agent electrolyte |
| CN112349962B (en) * | 2019-08-08 | 2021-11-09 | 宁德时代新能源科技股份有限公司 | Lithium ion battery |
| CN112420998B (en) * | 2019-08-22 | 2022-03-01 | 宁德时代新能源科技股份有限公司 | Secondary battery |
-
2022
- 2022-12-20 WO PCT/JP2022/046845 patent/WO2023162432A1/en unknown
- 2022-12-20 CN CN202280086003.4A patent/CN118451580A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023162432A1 (en) | 2023-08-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2023119946A1 (en) | Secondary battery electrolyte solution and secondary battery | |
| WO2024190050A1 (en) | Secondary battery electrolyte and secondary battery | |
| WO2023162432A1 (en) | Secondary battery | |
| WO2023119945A1 (en) | Secondary battery electrolyte solution and secondary battery | |
| WO2023162429A1 (en) | Secondary battery electrolyte and secondary battery | |
| WO2023162430A1 (en) | Secondary battery electrolyte and secondary battery | |
| WO2023119948A1 (en) | Secondary battery | |
| WO2022196238A1 (en) | Electrolyte solution for secondary battery, and secondary battery | |
| WO2023119949A1 (en) | Secondary battery | |
| WO2023162431A1 (en) | Secondary battery electrolyte and secondary battery | |
| WO2023189709A1 (en) | Secondary battery electrolyte and secondary battery | |
| WO2023162852A1 (en) | Secondary battery electrolyte and secondary battery | |
| US20240322249A1 (en) | Electrolytic solution for secondary battery, and secondary battery | |
| US20240322250A1 (en) | Electrolytic solution for secondary battery, and secondary battery | |
| WO2023120687A1 (en) | Secondary battery | |
| WO2023120688A1 (en) | Secondary battery | |
| WO2022172718A1 (en) | Secondary battery | |
| WO2024195306A1 (en) | Secondary battery | |
| WO2022196266A1 (en) | Secondary battery | |
| WO2023188949A1 (en) | Secondary battery electrolyte and secondary battery | |
| US20240322251A1 (en) | Secondary battery | |
| CN118369804A (en) | Secondary battery | |
| WO2024195305A1 (en) | Secondary battery | |
| WO2023162428A1 (en) | Secondary battery | |
| WO2022163138A1 (en) | Electrolyte for secondary battery, and secondary battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |